LETTER: Climate change magnifies dip in Charles River's water quality

Wednesday

Jul 3, 2019 at 9:00 AM

To the editor:

The report on the decline in the water quality of the Charles River (“Charles River water quality grade dips from A- to B,“ published June 24) is a reminder that stewardship of critical environmental assets requires persistent efforts. The Charles has made enormous strides since the mid-1990s, but holding on to those gains may not be easy.

As a volunteer in the water quality monitoring program for the Charles, as well as a recreational rower, I’m well acquainted with the primary hazards to the river, namely, combined sewer overflows and stormwater runoff. The city of Cambridge has reduced but not eliminated discharges from combined storm/sanitary sewers into the Charles in recent decades, and the city is working diligently on the stormwater problems. The Public Works Department has helpful information on its website about steps residents can take to mitigate harmful runoff.

Another threat to the river’s health is climate change. During the coming decades, the increasing water temperatures due to climate change will worsen algae blooms fueled by stormwater runoff. And because climate change favors weather patterns in which dry periods are punctuated by intense rainfall events, less of the precipitation percolates into the water tables on which the Charles depends.

Stormwater and sewer overflows are still the main culprits, but climate change, once again, magnifies the problem.